class Zcsh {
    public boolean isSubsequence(String s, String t) {
        int index = 0;
        for (int i = 0; i < t.length() && index < s.length(); i++) {
            if (t.charAt(i) == s.charAt(index)) {
                index++;
            }
        }         
        return index == s.length();
    }
}